(1) Field of the Invention
This invention relates to a dyed synthetic fiber having incorporated therein silver-substituted zeolite particles exhibiting an antibacterial and antifungal action, which fiber retains a high level of antibacterial and antifungal properties even though dyed, and to a process for preparing the dyed fiber.
(2) Description of the Related Art
It is known that fibers having incorporated therein antibacterial and antifungal silver ion-substituted zeolite particles and textile articles made therefrom exhibit a good antibacterial and antifungal action against microorganisms such as bacteria and fungi (see U.S. Pat. No. 4,775,585).
Antibacterial and antifungal composite zeolite particles having adsorbed therein a divalent metal ion such as a copper ion or zinc ion in addition to a silver ion through an ion exchange reaction also are often used because these divalent metal ions exhibit an antibacterial and antifungal action and a heat resistance, although the antibacterial and antifungal action is somewhat less than that of a silver ion.
Usually, a metal ion-substituted zeolite having adsorbed at least one metal exhibiting an antibacterial and antifungal action in the ion-exchangeable sites is incorporated in a polymer, the polymer is shaped into a fiber, a film or other shaped articles, and these shaped articles are dyed and finished.
However, fibers and other shaped articles prepared by a conventional procedure have a problem in that the antibacterial and antifungal action is reduced during the dyeing and finishing treatments. The degree of reduction of the antibacterial and antifungal action varies depending upon the particular dye, finishing agent and dyeing and finishing conditions, and especially, where dyed with acid dyes including metallized dyes and acid dyes (in a narrow sense), the antibacterial and antifungal action is reduced to a great extent and in some cases the antibacterial and antifungal action becomes almost zero.